Re: Path MTU for draft-ietf-v6ops-mech-v2-00.txt

[itojun@iijlab.net]

>> 	i don't understand your scenario.  even if there's IPv4-over-IPv4
>> 	tunnel with outer DF bit set, ICMPv4 too big won't get propagated
>> 	to IPv6-over-IPv4 endpoint, nor IPv6 source.
>What I'm trying to say is that there are implementations of IP-IP 
>tunneling (subsequently, IPv6-over-IPv4), which always set DF bit in the 
>IPv4 header.

	RFC2893 is rather clear about DF bit handling - it must not be set
	for tunnel with non-dynamic MTU.  so i would consider the above example
	as "buggy".

itojun